Persons whose close relationships are marked by features such as conflict and negative exchanges appear to have a higher risk of heart disease than peers with more positive close relationships, according to an article in the October 8 issue of Archives of Internal Medicine.

“An extensive body of research shows that social relations are associated with better health and reduced risks of cardiovascular disease,” the authors wrote as background information in the article. “However, contradictory findings on the health benefits of structural support and the limited protective effect of marital status against cardiovascular disease among women have stimulated further scientific inquiry into the quality of social relationships.”

Roberto De Vogli, PhD, MPH, and colleagues at University College London studied 9,011 British civil servants who completed a questionnaire about negative aspects of their close relationships either between 1989 and 1990 or between 1985 and 1988. Although the questionnaire assessed up to four close relationships, the researchers focused specifically on the primary close relationship.

In addition, participants answered questions about how much emotional and practical support they received from that person on a regular basis. They were then followed for an average of 12.2 years to see if they experienced fatal or non-fatal coronary events, including myocardial infarctions or angina.

Of the 8,499 adults who did not have coronary heart disease at baseline and who provided sufficient information for analysis, 589 reported a coronary heart disease event. After adjusting for other risk factors, persons who had a high level of negativity in their close relationships were 1.34 times more likely to experience a coronary heart disease event than those with a low level of negative close relationships.

The association was weakened somewhat but still significant after researchers adjusted for negative personality traits and depression. This suggests that emotions may partially mediate the association between negative relationships and heart disease.

“When one considers emotional factors and their biological translation into the body, research shows that negative marital interactions are associated with depression, often in combination with reduced self-esteem and/or higher levels of anger,” the authors wrote. “These emotional reactions have been found to influence coronary heart disease through the cumulative ‘wear and tear’ on organs and tissues caused by the alterations of autonomic functions, neuroendocrine changes, disturbances in coagulation and inflammatory and immune responses.”

Although women and those in lower employment grades were more likely to experience negative relationships, the associations with heart disease did not change based on sex or social position. In addition, heart disease risk was not associated with the level of emotional or practical support received.

“It is possible that negative aspects of close relationships are more important for the health of individuals because of the power of negative close relationships to activate stronger emotions (worrying and anxiety) and the consequent physiological effects,” the authors concluded. “In contrast, other more positive forms of support may not affect the physiology of individuals in a measurable or clinically relevant way.”